Hub unit having steering function, and vehicle equipped with same

Abstract

Provided is a steering function-equipped hub unit including: a hub unit body including a hub bearing; a unit support member configured to be provided to a chassis frame component, the unit support member supporting the hub unit body such that the hub unit body is rotatable about a turning axis extending in a vertical direction; and a steering actuator configured to rotationally drive the hub unit body about the turning axis, wherein the hub bearing includes an outer race integrally provided with turning shaft parts protruding upward and downward in the vertical direction on an outer peripheral surface of the outer race, each of the turning shaft parts having an axis coinciding with the turning axis, and the hub unit body is rotatably supported by the unit support member through the turning shaft parts.

What is claimed is: 
     
         1 . A steering function-equipped hub unit comprising:
 a hub unit body including a hub bearing configured to support a wheel;   a unit support member configured to be provided to a chassis frame component of a suspension device, the unit support member supporting the hub unit body such that the hub unit body is rotatable about a turning axis extending in a vertical direction; and   a steering actuator configured to rotationally drive the hub unit body about the turning axis,   wherein the hub bearing includes an outer race integrally provided with turning shaft parts protruding upward and downward in the vertical direction on an outer peripheral surface of the outer race, each of the turning shaft parts having an axis coinciding with the turning axis, and   the hub unit body is rotatably supported by the unit support member through the turning shaft parts.   
     
     
         2 . The steering function-equipped hub unit as claimed in  claim 1 , wherein the outer race is provided with an arm part configured to transmit a driving force of the steering actuator, and the arm part is integrally provided to the outer race so as to protrude in a horizontal direction on the outer peripheral surface of the outer race. 
     
     
         3 . The steering function-equipped hub unit as claimed in  claim 1 , comprising a preload applicator applying a preload to the hub bearing, wherein the preload applicator is a nut fastened to fix an inboard-side end of an inner race part of the hub bearing with respect to a hub axle part of an outboard-side part of the hub bearing. 
     
     
         4 . The steering function-equipped hub unit as claimed in  claim 1 , comprising a preload applicator applying a preload to the hub bearing, wherein the preload applicator is a crimped part fixing an inboard-side end of an inner race part of the hub bearing with respect to a hub axle part of an outboard-side part of the hub bearing by orbital forming. 
     
     
         5 . The steering function-equipped hub unit as claimed in  claim 1 , wherein the outer race is made of high-carbon steel, and a surface hardened layer is provided on the raceway surface of the outer race by induction hardening. 
     
     
         6 . The steering function-equipped hub unit as claimed in  claim 1 , wherein the outer race is made of case hardening steel, and a surface hardened layer is provided on an entire surface of the outer race by carburizing hardening. 
     
     
         7 . A steering system comprising:
 the steering function-equipped hub unit as claimed in  claim 1 ; and   a control device configured to control the steering actuator of the steering function-equipped hub unit,   wherein the control device includes a steering control section configured to output a current command signal in accordance with a given steering angle command signal and an actuator drive control section configured to output a current in accordance with the current command signal inputted from the steering control section to drive and control the steering actuator.   
     
     
         8 . A vehicle comprising: steering function-equipped hub units as claimed in  claim 1 , the steering function-equipped hub units supporting front wheels, or rear wheels, or all of the front wheels and the rear wheels.